In the novel Destination Unknown, Mrs Calvin Baker is woman who Hilary Craven met at the BakSt. Louis Hotel in Casablanca and later at the Palais Djamai at Fez. She is the typical "travelling American ... comfortably off, with an inexhaustible thirst for precise information on every subject under the sun."
Mrs Baker is described as short, plump, with well-blued hair. She did everything with a high level of energy and went out of her way to get to know and chat with any new people whom she met including Hilary when she first arrived at the hotel from the hospital.
Much later, Hilary would discover that Mrs Baker is an operative working for Mr Aristides and her job was to escort people who were making the journey to his secret research station in the High Atlas mountains.
Mrs Baker was a puzzle to Hilary, just like all her other travelling companions. Her job entailed that she changed identity frequently, and for this, the exaggerated external characteristics were helpful. After all, as Mrs Baker asserted, one travelling American is very much like another. But what lay behind the facade is not easy to fathom. Hilary tried to get to the real person beneath the cover but the furthest Mrs Baker would go was to say that she is finished with the United States. There are reasons she cannot return there. "If I can pay off a grudge against that country, I'll enjoy doing it," she says, with a momentary touch of malevolence in her expression and tone of voice. Hilary found, perhaps to her surprise, that those who worked for the Aristides organisation had very different motives. In the case of Mrs Baker, she concluded that it was simply the attraction of being paid a lot of money.